SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '93d15f2484ba8b0210038428e5c1c9038fcabdeaaddbc5ac40f6f2276d9450c2' 
  AND token = 'wcxDCZ1jSHCDQqGLi+jt0ScK5Y7T9bXJ9yVv5SrGoRs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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