SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '30f71ac94e55723d4f7975b7e9f6e7851dd4998b40d8718d6b26617ec518e888' 
  AND token = 'L++HGAXjSnstuyV6h3rrv+wDWX+GqPZAQuCtGrBXoyo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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