SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e16aa48bf73ef325c8643b92fe7d9bb72e522434cff44616f6b37c6654ec4b33' 
  AND token = 'qmMVOlGWCxbzwFj2fDhpQG20M/j1rM+s6f8zltCDqKY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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