SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ef6f10fcb2d3255fb9a0222b5542ef03e1b77ea956a262840e008b73fe925ae4' 
  AND token = 'yAkA7dcALJVqUZ3YN+AnQ74Hm9HpicRsleDwr1Sf8bc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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