SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b84bed4c56204c738450da5a1d6a2b42a67b564dc5b5fa751027fe12088c33d5' 
  AND token = 'w1xsem9JJ2QM+grBujXC63dhGsEeazJQdWYwngejmPU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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