SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ea596114c8b3681d74eafcd1f3e790c732b735d8ee52b5df1c9d73455dc483f9' 
  AND token = 'pQWTHJ1TZT6yXufX8kNhjb+TT7b1W1v+SAXgOP8xqQk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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