SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2dd49591e16550153bec31c0294da71393002bdb409643c325df3fa2764a65f9' 
  AND token = 'W12BLqmK1k/6oq7ig47x/NB/Ca+jETSh0B/4YrCCLag=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00050

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}