SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '770d6c0dd8bdc859fafde5fa4eb3fd6058c7d06a9b0670a35b55653472dfb312' 
  AND token = 'S+8xKpCtNEXrWIoWv6FcCr/AxXu3zDy2MaDr2YDzBKQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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