SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a57bbff0485f7a9f15e0dedc57a95f9535b2b871aef535441c972b73660ee153' 
  AND token = 'StbOAWfBiG+tVQww/MH5FAhiSNaoHqs/csFZzQrwfeI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}