SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '049bab2f6713f40978718642ddb6c7294e2c50e39aef1c1d1170481936bc7097' 
  AND token = 'EQI6CVOF4lPOZqzIYG0W2MXGuFvCXkxDuBbVQJjl64g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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