SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '45b96ebe4622c184f64186462ba55a650259e53470847be399cc21437aebeac4' 
  AND token = 'fIyAfWyjKXBoM2D1hHIBDz/JDqbX5nrBjvPTr8SYafY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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