SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3e30cc9d69d17500ed238a587d0e827a596e25db3c41cfba125445b3417d2e4d' 
  AND token = 'k5afbyZ9L68aFzPZCW14zeLzDYXlPFYovnbdC0KZaVk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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