SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '756724c2674a0c715e176c9b9befd4d72e8c151092b222bf8bd9580703853958' 
  AND token = 'I1SdGoIEuhdYeUcNGdtVSFeEy4pysn3TccfcPIcwE/M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00058

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}