SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9891639bb3a38cafe6c31d9430aa9508ca77070d26bdd71c453e63665bb7fb0b' 
  AND token = 'XADM70Uho6nza+MRknsDtKfTpFwJviFgALZNIaftyOY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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