SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bb83589c5016d0799e1a29a32da283027c2c645ecbf05347ccfe14266847a85e' 
  AND token = 'DXn2D5s4TX8/OJGEqimfpLGKpWSbOx25DZ9StgIzrbg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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