SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7265908d3c729365aa074d994e15f1032b3b0b4852afb01cf35d6c559d18a867' 
  AND token = 'xCSX0ZQHwLxdFHmiSNmqmvEgBwCTEOFol6NSeRGpiJE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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