SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '33aaa141d0dbab2acbddcfa1c184158fad2c8af3a3cd05dd8bd7d5f0e9d3f30c' 
  AND token = 'cHsnNSzGwgL0+YoMGv+G6V4v+pzFpKNUsqNOZqcr3X4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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