SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '59595a65346dc8371ba647f33cbd68a44c5860d84ab64793afd98c8649219b2a' 
  AND token = 'rEuV2vQ3lk6gKjgxMX3S5KQU8heLYXycwhyb2rjNxTk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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