SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5f84fbc51a6af473ecb6c27d73775b594c25b20094b93d6bd0da98efc820acc9' 
  AND token = '/34Mfbkh/X+kCvnuXY6MIijiK1xaPU5C5RIGJADiM3s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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