SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '580e7f04298f3e38609b2409818cbb03d633dddb79e2a1c8beee8e7742cc64ab' 
  AND token = 'hb5nAy4dFEwTeZS1KNHaJy23phDHDhRAmnEWDshzODY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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