SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e4ade6802a4adb39e6cd4ebbba12293bb546a5d0b77614158bc166381563d490' 
  AND token = '6ldRkoC329GChbUTgbPIKTOxdmuKN6k0Qf4P8DNQa7c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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