SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fb17888429b9af34d2a2bdb035ca59950203403f497de39d1c4e9b5070c51d04' 
  AND token = 'L79N9SKQ4aRZE/ISHeXadkJQ1xz6QVL9uC/EsogxaE0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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