SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0c2a6c3a0440497f6c94ca29549a6d2dcba92074334d521500e3c84315c47181' 
  AND token = 'hEfboRpIRbxew8VxHGM0Fwet38HTawD1eChbirOhO6g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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