SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ee4fb347a2c767f428f86cff6311964aa76db224256525750d3c279bee2d8258' 
  AND token = 'KJBvnsszPfmrumxHH7R33vccaSe9SDlVQmc9iY88eGM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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