SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'abf24ed1f0547b89b96a55ffcd2697f782722d5a0414db91f24921e82ed76869' 
  AND token = 'ooEAcGkVyfpskk4ZpYhAYXvUOBAykQNkJIcQLYnK9+o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}