SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '29d9a06de571c6336ac0f2259fdd1543685ebf170b2c3e70ab42618ffeeeef51' 
  AND token = 'Usyk0CUsHG3/XsaFCOXHUREAnZ5kx5Csp9OjX7UHANc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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