SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '68663878d217915de748a4d4f05bd848b524fe3b6f985d252fb21b0ac6ec8c7a' 
  AND token = '6q95evMbnW9foWEMRf+2shg3HKYU0YRU5NTF5eD4tT8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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