SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dd809ba67ce6e49076268e5a983c3f05546fd6931be9716d84ed6b2ccc227741' 
  AND token = 'XpQyzBHvBeE+Kr0xQUBda9f3yoElYGrAJ09SPbkAXcI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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