SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '32459de5365342d435fe2848bc80699b5df593836c063a45c8d2037dc5256ff2' 
  AND token = 'J7EMIMHHlA0OnKjGfg7TqdqWuMOTTWcTCymfzJTRAWc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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