SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'caca0b3273df98ba82b9363d4ebbdef6c36c25614b940d9d3625c32bc274fa86' 
  AND token = 'a4lmw1gD5aBLDLknteu7LojMRZgClmLeEsJz08/04nU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00070

JSON explain

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