SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7f680cdf10a685294609c42f56be6cb3d484df6f46223d170396c68471667534' 
  AND token = 'y0lWUb2Cx+j9jVpNDWHqBq9cpoz3sWjIzgqJeAk2/Rw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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