SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cf8ee7a027c42c3822826eef23b13dba43f6d666b9044ec97a768598ec578a07' 
  AND token = 'ZHhcRQzPqzyOAyRQoNKGnnaksVWHeJDkj/GKNAFWgHA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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