SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '52b154acb7828e62759cb9fe22a9eaa0fe99168d9e54ba31b60f6f28aa3321fd' 
  AND token = 'hyxRRULxZzW+pvYuYV2nB1jMdlqMiTLRmikHMpj+5tU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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