SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '331c716068d04dce4fbd0719a5501b76c0ce90129116f26f5d9c081f20632177' 
  AND token = 'CuKx7woWFY+Gmpbma09SjjaXMYrAPyRmNbZBHnBfk0M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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