SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7428edbac847e1ab7d9aef20ae1f034a649ba58522338ff17d0cc4b8a1ff1354' 
  AND token = 'ExF1vx40Xhpc+RluHp39J6w/M4CzK+0wQQmwnfvmWxY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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