SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '287c97777987ebd39c783089b7d78a4e1970128b4c9009854bf687683f32816b' 
  AND token = 'DFsphwkQSeq24lU0W1jy+YYxhvtL2fhdo9Wjewowq4Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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