SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9c5968dac2bb134983fd854dc2eb59342916fa4d2ffb0da00972c9d633ab2196' 
  AND token = 'zl/ON8jDkC0wgORVAkmXtxGnX9lvF0zYzsKVJkn8pko=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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