SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '662cc904536e49b77191f730aa86d1acac11fa5219cd8cee2a09a6f1e3aae85d' 
  AND token = 'qJLCDe4XKMZOzhW/9SpLy+4cWSMDrHnjqoUg3eUSCnA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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