SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1ee98294fdf3f7d1657827a13eefa2c8bb2f554cebcb7f915f29545e0f52241a' 
  AND token = 'YW4tkD/ZqH7s2zcGqHBfWV2lBIdvqkjtajuNazUsBCg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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