SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '102309c9cfca1ebe06223a4f5418ef26917304c219284556bcccb1a0bc570d08' 
  AND token = '9DgDMMyHeAml5k/cSDpAuWI2gXJymBTaNaPxkmulpUE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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