SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '981ebfae47f9cd9ea3957a41c279abd0776aabf3da41fbd24d0b7d7bd296bbec' 
  AND token = 'C2ZpUjbBpoldzmvm9sRda5BwFzpIME49XjPegB5B8SI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00050

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}