SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '27fa622eff8ffc363e24fb044992a22fa029c20ccdd5f7ce7b6e4226db58906b' 
  AND token = '5YURQJOMCh2ptWqlGiO7aEul5thVvtGswsv+tUfAiAo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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