SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1f33f5d80bb8d1d26c442a8f0e10d6638e47bd280172172b073dfa9c27797840' 
  AND token = 'TsX/vtr/K5i6jHj4wx6ZX2vLV2Bb08vEQBlMYwnt+Mo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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