SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a68f8af2e4fd544d8ae7f02d4021f731038292dbd2323e257e9efaf9b6557af7' 
  AND token = 'T/qCTWMKJxUVGNDtW5WmA1r9sUkMkAeYNbv2BBmJE4Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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