SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a697939166ec200e0bddbaf87330e3ee26d32a00922f2f9c2ce3e603f96c7051' 
  AND token = 'K1vTLBBGR6gfjAcA9nOgpNoQ5UvIRsTTKeSsWlphwJU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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