SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5489247d591fd6a94f4c69e0cbb1759b2f0e18da2783438350370df627b392f8' 
  AND token = 'KqaybhK9pu1k5xQfdl64Cm7JP1MBGSrezcvMyHlNqVE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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