SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '64aac1780f2d3c07c91072e77574f4a5015323256236ebaf9f646aecdc8d3116' 
  AND token = 'pWPK9t24EId9/AxE18ed0zdEfhiu38dnePS+lKuUCmQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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