SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e78bdf140ee7fb3197d39c2588ff202d8b14ee09ce7964df30034094be651e87' 
  AND token = 'AWA/kQgNt4txvraOEE/75FEs/HQxyRAO1K1L1qYFO9U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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