SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c3aae227f199ff28a682074cb03c1683e0708bbfb082b513ce50fe384608f658' 
  AND token = 'Bhejn60lPVvmNGCJ98YIP6y1vxFYAO1r4l3guvvvOIc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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