SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c1ced6361caff55952052e26e4d05a291113af1067b5006ba456f627fa29329b' 
  AND token = '+mcUpZKJAhPA93aEB7z1ccZGQwOXpD8qzKbRr49GgCo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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