SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '10b679679b613866ca574119ddeb44c14959817b340df8f0e050c153e8ff6402' 
  AND token = 'YKPHANAlv/OUA/byDsSkbBQg6dyOFyqepSDMZjDiTgQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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