SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5d0fb8849314fffce70d22fdde6a25e4fda35cdb6cd63ecfaeceddd008aebb83' 
  AND token = 'm0YArSn623Fvr52Kjd9SXtq08X5zUR2aiMGOUjRpZM8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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