SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b0205847c372aa58fbdffdb102341daa42a57d74b31c0661660184b09b193cb3' 
  AND token = 'fzdfgxYBZGxGqOgdnMBcFlZgcx6UhA3us4HdHeGA+f8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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