SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e19c6abcecd947cbef7842de26cc046337aace7d2ca9e067befc766828be98d1' 
  AND token = 'y0IVAFiIuiYb6FIPTik2i2Eu7Dlyf2Eg0+wzhFFBag8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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